1. Field of the Invention
Embodiments relate to an apparatus and method for measuring a quality of a holographic image, and more particularly, to an evaluation method of objectively quantifying and efficiently measuring a quality of a holographic image displayed in a three-dimensional (3D) space, to evaluate the quality of the holographic image.
2. Description of the Related Art
A holographic display technology is an ideal, completely realistic three-dimensional (3D) display technology. The holographic display technology may display a wavefront generated on a given object without a change, to provide the same effect as if the object really exists to user's eyes. In particular, unlike a stereoscopic binocular disparity scheme mainly used in a current 3D display industry, there is no eye strain and dizziness, because inconsistency between accommodation and convergence does not exist. Also, the holographic display technology may enable observation of different images based on a change in a viewpoint, and may be regarded as a ultimate 3D display technology because it is possible to view a plurality of images without a need to use an additional device (for example, glasses) for viewing.
Accordingly, currently, in all countries of the world, a variety of research has been conducted on a new display system obtained by combining a display device that is currently available in common with optical and machine systems, along with active research on display devices. However, to realize the holographic display technology, there are a few requirements.
The requirements may include development of a spatial light modulator (SLM) or a display apparatus for displaying a stereoscopic image with a good quality, an optical-wave illumination unit for providing coherence/parallel straight light characteristics that may induce interference between optical waves, and a method of measuring a quality of a stereoscopic image displayed in a space.
Due to an extremely narrow range of a viewing angle and an extremely small holographic image expressed by only a display device that is currently available in common, it is difficult to actually observe characteristics (for example, a motion parallax, consistency between accommodation and convergence, or a binocular disparity) of a holographic display as an ideal 3D display. The above display system may occupy a relatively large space and may require an optically precise arrangement process, and the like. Also, a holographic display may mainly use an illumination light source with coherence, for example, a laser, however, directly seeing the illumination light source with eyes for a relatively long period of time is dangerous. Accordingly, to prepare an optimum image in the holographic display, a user may need to indirectly observe and view images through capturing of a camera in most cases. Thus, an evaluation method of objectively quantifying and efficiently measuring a quality of a stereoscopic image displayed in a 3D space using an SLM to evaluate the quality may necessarily need to be provided to holography researchers and holography viewers.